According to Deckard Cain, Tyrael "was renowned for being calm and controlled and meticulous in his execution of combat technique." Tyrael's weapon is the legendary El'druin, the Sword of Justice, and he was known in the ages before the rise of man as being at all times fair and impartial, as Justice should be.

Though relatively little has been revealed about Tyrael's activities prior to Inarius's betrayal and the Sin War, it is known that Izual once served under the Archangel of Justice as his "most trusted" Lieutenant, but eventually chose to lead "an ill-fated assault upon the fiery Hellforge", resulting in his capture, torture, forced betrayal of Heaven, and fall from grace. It seems also evident that Tyrael clashed himself countless times with the forces of Hell, and at some point encountered and likely fought against Mephisto and Diablo, two of the Prime Evils.

While Tyrael's personal relationships with most of the other members of the Angiris Council remain vague, it is known that in ages past, he was a battle-comrade and "old friend" to Imperius, the fierce and valiant Archangel of Valor, and that he was especially close with Inarius, whom he considered his "brother" due to their similar resonances. Furthermore, at some point in the Eternal Conflict, Tyrael ordered the construction of the Pandemonium Fortress to hold the monolithic Worldstone, the Eye of Anu, over which the Heavens and the Hells clashed so fiercely.

Roughly three thousand years before the darkening of Tristram by Diablo, a farmer by the name of Uldyssian decides to embark on a mission to destroy both the Triune and the Cathedral of Light, his latent powers secretly awakened by the disguised demoness Lilith, managing to first decimate the ranks of the Prime Evil-founded Triune.

While Tyrael does not appear in person in the first novel of the series, he is mentioned in Birthright by his brother, the renegade Inarius, when the latter recalls his time serving as a commander of the High Heavens and his failed efforts to make even Tyrael see "reason" and realize what he saw as the ultimate futility of the Eternal Conflict. Towards the end of the Scales of the Serpent, Tyrael, though not mentioned by name, tells Achilios that he has need of him, renders him unconscious, and spirits him away. Rathma, Mendeln and Trag'Oul are unable to find any trace of Achilios, and, noting the absence of the Burning Hells' foul touch, realize that "another angel" other than Inarius has taken Achilios, meaning that Sanctuary had been discovered by the High Heavens at long last.

In The Veiled Prophet, Tyrael seizes control over the undead Achilios and forcibly has him target his old friends, including Uldyssian, in the hopes of eliminating what he saw as key threats and unnatural blights upon Creation, but Achilios's sheer willpower manages to narrowly enable him to avoid killing them, to which Tyrael responds ambiguously that his strength to resist even his commands could "change everything". Trag'Oul and Rathma soon surmise that but one of the Heavenly Host has come, and in secret, to Sanctuary, seeking to judge both Inarius and Sanctuary, yet deliberately not immediately calling down the rest of the Angels - the one who had been closest to Inarius: Tyrael.

Diablo, when contacting Inarius while hoping to make an "alliance", initially appears in Tyrael's form in an attempt to intimidate him. Later on, the true Tyrael, along with Achilios, appears before Serenthia, claiming that, while he had sought to slay her and Uldyssian before, his plans have since changed, and warning her of both Inarius's secret pact with the Lord of Terror, and of his using the Worldstone's power to vastly augment his own. Rathma later meets with his father and tries to warn him of Tyrael's presence, but an arrogant Inarius overrides and banishes him.

Serenthia and Achilios find and attack Uldyssian, whom both genuinely believe, due to Tyrael's manipulations, to be possessed by Malic, only to find that Tyrael has deceived both, for the purpose of maximizing chaos and sending Sanctuary's few remaining capable defenders into disarray in preparation for the coming of the Host. While Tyrael is later surveying the situation from among the clouds, he declares that it is "good", silently noting the potential threat of the angel/demon spawn, and recalls that though he had briefly contemplated suggesting the use of the mortals as soldiers for Heaven, the thought of fighting alongside any demon-tainted strain made him completely reject such a notion, believing that soon, the "blasphemous creation" of Inarius would be ended.

When the Host at long last reaches Sanctuary, just as Uldyssian was about to defeat Inarius once and for all, Tyrael intervenes directly to bind Uldyssian in place, telling him to "accept what must be", as outright and devastating war erupts between the four factions, and though Uldyssian manages to break free, Tyrael is gone and only Inarius remains. Uldyssian taps into his full potential and might in order to dispel the forces of both Heaven and Hell, but soon realizes that the raw power he had unleashed was threatening to destroy his entire world. After Trag'Oul tells him what must be done to save the realm, Uldyssian willingly sacrifices himself, thus saving Sanctuary, all those he loved, and, perhaps most of all, his own humanity.

When the Angiris Council comes to judge Sanctuary, the five debate intensely about whether or not to spare Sanctuary. When the vote deciding the fate of Sanctuary was given, Auriel and Itherael voted in favor of Sanctuary, believing that humanity's potential to serve the Light could surpass even their roles and that the Conflict might be ended for good, while Imperius wanted to eradicate the world of humans and Malthael abstained. Had Tyrael sided with Imperius, who expected him to cast the deciding vote against Sanctuary, the resulting tie would have destroyed mankind anyway, and thus have made Uldyssian's sacrifice for naught. However, it was then that Tyrael, shocking even the humans, had a change of heart, telling the Council:

...THIS THING GREW... AND GREW... UNTIL IT BECAME WHAT NONE COULD FATHOM, WHAT NONE COULD HAVE EXPECTED! THIS PLACE CALLED SANCTUARY HAS BROUGHT FORTH SUCH AS WE HAVE NEVER WITNESSED, THINGS I MYSELF CALLED ABOMINATIONS! Before Imperius could interrupt, Tyrael pressed, BUT ABOMINATIONS DO NOT FEEL SUFFERING, THEY DO NOT STRUGGLE FOR ONE ANOTHER AGAINST GREAT ODDS AND THEY DO NOT... THEY DO NOT... OF THEIR OWN FREE WILL... CHOOSE... YES... CHOOSE TO COMMIT SUCH GREAT SACRIFICE FOR THE SAKE OF OTHERS......I DID CALL THEM ABOMINATIONS... AND I WAS WRONG! MY VOTE IS FOR THEM... FOR I WOULD SEE WHAT THEY MIGHT BECOME... AND MARVEL IN IT.

This single decision by Tyrael would forever alter both his own nature and that of both Sin Wars, and from then on, growing endlessly fond of humanity and deeply impressed time and again by its innate potential for greatness, Tyrael began to intervene more and more frequently on mankind's behalf against the Burning Hells, even going as far as acting against the mandates of his fellow Council members in order to protect the race he now cherished most. Ironically, he who once callously manipulated and tried to annihilate humanity would in the following millennia serve as one of humanity's greatest and most devoted allies of all, understanding that perhaps not everything was so easily defined by mere laws after all, and embracing humans not as unnatural abominations, but as valiant and truly great "heroes", as he would call them, for the Light.

After the Dark Exile, Tyrael was the one responsible for establishing the Horadrim in order to protect Sanctuary from the Prime Evils and the creation of the three Soulstones from the Worldstone itself. Moreover, he helped Tal Rasha and his fellow mages to imprison Baal, offering crucial aid and advice to them. Tyrael's actions caused the Horadrim to hail him as their "Savior", for without his aid, Sanctuary would have long since fallen to Hell's unholy slavery.

When Diablo was freed again, Tyrael openly intervenes, even directly grappling with the Dark Wanderer to stop the release of Baal, but ultimately fails to stop the Prime Evils because of Marius removing Baal's Soulstone from Tal Rasha's chest. Ensnared by Baal's tentacles and bound to the Binding Stone in Tal Rasha's Chamber, Tyrael is eventually freed by the player and travels to the Pandemonium Fortress where he gives the player the quests to destroy Izual and finally Diablo himself. He is unable to overtly help the player because according to his own words, he was severely weakened by Baal, who damaged the forces that bind him to Sanctuary, and also because he was wary of what could befall Sanctuary if the High Heavens were aware of the corruption that had so tainted it. After Diablo is defeated, he opens the portal to Harrogath.

He appears again in the Lord of Destruction, when Baal is defeated, having been rendered incapable of direct intervention due to the Demon Lord. He informs the player that the Worldstone, which had been corrupted by Baal, must be destroyed in order to safeguard Sanctuary, and subsequently does so with his Sword, but not before sending the heroes to safety. Tyrael's fate has been left to speculation, since he has been missing for the last twenty years after the destruction of the Worldstone.

Tyrael has the appearance of a tall, imposing humanoid. He is clad in burnished bronze and golden plate armor, and has tendrils of light coming out of his back which also double as wings. Although he is described in the Diablo II manual to be "beautiful beyond comprehension", in game his face is a featureless mask of darkness.

Tyrael's tendril-like wings, being made of holy energy, do not seem to stay a uniform length. While in the Pandemonium Fortress they seem to be only a few metres long in length, they are wider than the span of the Worldstone itself when Tyrael destroys it. They can also be utilized to ensnare foes or manipulate objects (such as closing the door to Tal Rasha's tomb after he and the Horadrim imprisoned Baal and Diablo.)

Even before his change at the end of the Sin War, Tyrael, "not sounding sanctimonious like Inarius but rather simply stating a fact", told Uldyssian to accept the inevitable end. Furthermore, unlike Inarius, who sought to humanity to fuel his own vanity and ego, or the Prime Evils, who sought to use humanity as weapons against the Heavens, Tyrael seems to have marked Sanctuary for destruction not out of particular hatred or cruelty, but because he truly finds doing both righteous and necessary - the execution of his inviolable and sacred Justice. Tyrael has gone to great lengths to uphold this Justice, even directly interceding whilst attempting to prevent Imperius from slaying Diablo. Also, Tyrael is notably the only member of the Angiris Council to of his own volition undergo a truly drastic change in personality and worldview.

In Diablo II, Tyrael appears as a positive character, personally protecting the last of the Horadrim, Deckard Cain, and constantly offering considerable advice and aid to the player, transporting them around the world and telling them ways to save Sanctuary from the chaos of Hell. He is very concerned for mortals and is always seeking to aid them in their battles against the Prime Evils. He is (as far as immortals go) a friendly and approachable personality. Compared to some of the other members of the High Heavens, Tyrael is also somewhat impatient and belligerent, as evidenced by his eagerness to help the mortals in contrast to his peers' aloofness, and his berating the player for arriving in Tal Rasha's Tomb too late.

As the Archangel of Justice of the supreme Angiris Council (thus described as being the "essence" of Justice, by Inarius, and champion of its aspect, by Mephisto), Tyrael is one of the mightiest and highest-ranking Angels in the High Heavens. In the Sin War novels, he displays enough power on Sanctuary to restrain even Uldyssian (albeit through exploiting his weakness) and easily render unconscious and seize control over Achilios, almost forcing him to slay his friends against his will, also providing him with a never-ending supply of sharp, and in some manner, magical arrows. Tyrael can use his tendrils of energy, or his wings, to physically hinder and grab onto other objects and characters.

Capable of rapid flight (like all Angels), concealing himself from the sight and magic of others, even the likes of Inarius, resurrecting Mercenaries, appearing at will to mortals, projecting the souls of humans across vast distances unhindered by physical barriers (as he did with Serenthia when he sent her to Kehjan by touching his palm to her forehead, though this seems to be at least partly illusory), contacting the other Angels across dimensions, and opening temporary portals to various locations, such as the cities of Lut Gholein and Harrogath, Tyrael is said to be "naturally far stronger" than his brother and fellow Archangel Inarius, whom he conceded as "powerful, but no more so than any on the Angiris Council", and who is the mightiest of all the Angels and Demons who created Sanctuary. In the past, at least in the time of Siggard, Tyrael has actually manifested himself in human form, clad in grey, with a musical voice, eyes sparkling with life, and a long mane of blond hair; in this shape, Tyrael seems especially benign and has claimed that it is "very difficult" for the most powerful Angels to appear on the mortal plane, and that even he cannot manifest himself for more than a night at a time.

While palpably formidable enough to dominate Diablo in his Wanderer form, Tyrael apparently lacked the strength to take on both Diablo and Baal at the same time, and for all his power and authority seemed "unsettled" when he spoke the name of Diablo, who he deems to be the "worst of the Three". In addition, in the scene with Marius, Tyrael seemed to have either slowed down the passage of time itself or brought himself and Marius to another plane briefly. Notably, Tyrael was able to destroy the primal Worldstone artifact with but a single strike from his signature weapon, the ancient Sword of Justice.

In Diablo II, Tyrael appears as a questgiver at the Pandemonium Fortress in Act IV,

In the expansion, he also provides the services of a mercenary captain. Contrary to popular belief, he takes gold to revive mercenaries, leading to many calling him a money-hoarder. Blizzard jokingly explained this behavior by saying that Tyrael has to pay certain bills. He also opens the portal to Harrogath. Tyrael can be seen in four Diablo II cinematics, and in Diablo 3 teaser trailer.

Tyrael, along with the rest of the Angiris Council and Diablo himself, has been confirmed to reappear in the third game. In the Opening Cinematic, Tyrael is shown, along with Auriel, Imperius and the Heavenly Host, to be fighting the endless hordes of Hell, masterfully wielding his Sword of Justice against them and eventually facing off against Rakanoth, the Lord of Anguish and servant of Azmodan. In the Prophecy, mentioned in both the Cinematic and the Book of Cain, it is said: "...And, at the End of Days, Wisdom shall be lost as Justice falls upon the world of men."

As with Diablo himself, Tyrael makes an appearance in World of Warcraft. He is a non-attacking pet, offered at the World Wide Invitational along with a beta key for Wrath of the Lich King, inside a goody bag. It could also be won on different WoW fan-sites, along with the beta keys.

A mount called "Tyrael's Charger" was offered to players who agreed to the annual pass for World of Warcraft, which guaranteed free access to Diablo III upon its release as well as guaranteed beta entry for the next expansion. The mount is a horse in golden armor with Tyrael's signature wings.

Tyrael, in Diablo III, is voiced by Jonathan Adams. Adams is an actor, but has also done voicework in television and games, including the show The Avengers: Earth's Mightiest Heroes, and he was the voice of Galactus in Marvel vs. Capcom 3.